It is well known that respiration modulates the heart rate (respiratory sinus arrhythmia, RSA). Meditation techniques such as yoga make use of this principle. The variation in heart rate or heart rate variability (HRV) is attributed to the autonomous nervous system (ANS). An increase in heart rate is attributed to the parasympathic (vagal) nervous system while a decrease in heart rate is attributed to the sympathetic nervous system. In meditation techniques (such as practiced in Zen Buddhism) the low frequency part of the spectrum of the heart rate variability is increased with respect to the high frequency part of the spectrum. This is regarded as beneficial (relaxing) for the well-being of the individual that is practicing the meditation.
In order to assist individuals, it is known to provide output to a user. For example, United States of America Patent Application Publication US 2005/0209503 discloses a method of presenting audible and visual cues for synchronizing the breathing cycle with an external timing reference for purposes of synchronizing the heart rate variability cycle with the breathing cycle. The method of presenting audible and visual cues thereby helps a user achieve coherence of the heart rate variability cycle. A family of audible and visual indicators is specified for purposes of communicating breathing phase, change of breathing phase, progression of time within a phase, and progression of the phase relative to the internal perception of the practitioner.
This technology and other existing applications such as Heartmath (available on the World Wide Web at heartmath.com) and Resperate (available on the World Wide Web at Resperate.com)are all focused on a single user.